My purchased songs don't show up on my iPod

Question

I have one of the first generation iPod Touch.  I've purchased songs and they show up on my music in iTunes but even after synching they don't show up on my device.  Can't figure out how to get them there.  Any ideas?  Since Apple change the version of iTunes I can't figure out how to synch after i buy something so usually end up disconnecting my device, reattaching to my computer and then it synchs.  Apple support have been absolutely of no assistance.

Answer 1

Automatic syncing is controlled (set up by the user) using the iPod's Music tab.  Select the iPod in the sidebar, under DEVICES.  Over to the right (near the top), there is a row of "tabs" (they look like buttons in the latest iTunes), that starts with Summary.  Click on Music there.
Make sure Sync Music is checked.  Below that, you tell iTunes how you want your iPod synced with music.  If your entire iTunes music library will fit on the iPod, you can select Entire music library.  Then, any change to your library (such as purchasing new songs from the iTunes Store) should automatically sync to the iPod. 
Otherwise, if the entire library will not fit or you don't want to fill up the iPod with only songs, you need to set up syncing based on Selected playlists, artists, albums, and genres.  Below that setting, set up the rest of the Music tab to tell iTunes what playlists, artists, albums, or genres to sync.  Only the songs included in your selection will sync to the iPod, so if you purchased new songs, they will not sync to the iPod unless thay are included in the selection on the Music tab. 
One easy way to set it up is to create a new playlist in iTunes, and call it something like "iPod songs."  From your music library, add ALL the songs you want on the iPod to this playlist (including those new songs).  On the iPod's Music tab, select this playlist for syncing.  Going forward, any change you make to this playlist (adding or removing songs) will sync to the iPod automatically when it is connected and you tell it to Sync.
You can also set up the other tabs, such as Movies and Podcasts (and Apps for an iPod touch), to set up syncing for those other categories of media.  Just make sure the total size of the selection is less than the capacity of the iPod (shown on the "bar" near the bottom).
All of the above has not changed for the latest version if iTunes.  It works the same as before...